As is well known in the art, sprinkling or fire-extinguishing systems typically include a plumbing array installed or attached to the ceiling of each floor of a building and having a plurality of sprinkler heads extending therefrom. The sprinkler heads are usually disposed at fixed distances such that water passing through the heads will affectively cover all of the floor surface in the building. In order to prevent the flow of water from the sprinkler system until such time as a fire condition exists, and then only in that portion of the building where such fire condition exists, there has been developed a variety of triggering devices. Such triggering devices are typically positioned within the sprinkler head and include at least one component made from a fusible or meltable material. The fusible component serves to release plug components when heat is applied thereto, allowing for the flow of water. See, for example, U.S. Pat. Nos. 329,311; 615,270; 1,160,517; and 1,233,289.
A major drawback with systems of this type is that from time-to-time the triggering devices would fail. In the past, in order to repair a sprinkling system after the failure of a triggering device, the entire system needed to be shut down. Thereafter, the sprinkler head would typically be temporarily plugged by literally hammering a frusto-conical shaped wooden object into the head opening. The system would then be reactivated with the wooden plug preventing flow of water from the sprinkler head. In order to repair the damaged sprinkler head, the system would again be shut down while repair work took place. As can be appreciated, significant periods of time would pass in which the sprinkler system would be deactivated, assuming the sprinkler control valves can be located prior to the occurrence of water damage. The only alternative to completing repairs to the system would be to allow one or more sprinkler heads to remain inoperative.
In order to alleviate these problems, substitute plug devices were developed for insertion into a sprinkler head after a failure occurred. Wells et al U.S. Pat. No. 2,520,588 discloses one such shut-off device. The shut-off device is placed into a sprinkler head after a triggering device failure and allegedly operates to quickly seal the sprinkler opening. The problem with Wells et al is that once it has been properly placed into a sprinkler head, the system must still be shut down and repaired in a manner virtually identical to the wooden-stake shut-off. In other words, a Wells et al shut-off does not provide a complete solution to the problem.
Similarly, DeGroot et al U.S. Pat. No. 3,223,171 is another attempt at solving the problems associated with the wooden-stake cut-off procedure. That patent discloses two telescoping members containing a compressed spring as being held together by a single pin. Axial removal of the pin allows the spring to force the telescoping members to extend, which, in turn, forces a resilient member over the opening in the sprinkling head. However, after the DeGroot et al device has been installed, no provision is made for thereafter triggering the sprinkler system in case of a fire. Consequently, the entire system must again be shut down so that the DeGroot et al device can be removed and replaced with a heat-sensitive triggering device. DeGroot et al possesses yet another problem not encountered with the Wells et al shut-off device. In order to stop the flow of water in a sprinkler head, pressure of at least 100 psi must be exerted against the sprinkler head opening. Consequently, the spring which is compressed between the telescoping members of the DeGroot et al device must be capable of providing sufficient pressure against the resilient member. It has been discovered that the force required to compress such a spring between the two telescoping members also provides for a significant amount of friction when the telescoping members are held together by a single pin requires axial movement for removal. This friction has been determined to be so great that it would take a significant amount of time, if it could even be accomplished at all, to remove the pin while exerting great force. It is believed that the time and the force required to remove the pin would result in the occurrence of unwanted water damage.
It is yet a further object of the invention to provide a sprinkler head cut-off device which can be utilized in both recessed and conventional sprinkler heads. Still further, DeGroot et al device is not capable of use in a recessed sprinkler head system where a portion of the sprinkler head is positioned in the ceiling. With such system it appears impossible to remove the pin after the cut-off device has been inserted, notwithstanding the friction problem previously discussed due to the confinement of the sprinkler head. It is, therefore, broadly an object of the present invention to provide a sprinkler head cut-off device which can be quickly and easily installed after the failure of a triggering device.
It is another object of the invention to provide a sprinkler head cut-off device which can be installed after the failure of a triggering device without having to shut down the entire sprinkler system.
It is yet another object of the invention to provide a sprinkler head cut-off device which after installation also serves as a substitute triggering device.